Question
A and B can do a piece of work in 30 days and 40 days,
respectively. They began the work together but after a certain time, A leaves off and B completed the remaining work in 26 days. After how many days did A leave?Solution
Let, after x days A leave. Let the total work is the 120 units (LCM of 30 and 40) Efficiency of A is 120 / 30 = 4 units The efficiency of B is 120/40 = 3 units So, after x days they both work together. According to the question, (4+3) x x + 26 x 3 = 120 Â 7x + 78 = 120 7x = 42 Â x = 42/7 days =6 days.
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